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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Lucene Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

22 results found.

  1. GRB 250419A: KAIT optical afterglow observations
  2. Konus-Wind detection of GRB 250403A
  3. GRB 250403A: VLT/FORS2 spectroscopic redshift z = 1.847
  4. GRB 250403A: AstroSat CZTI detection
  5. GRB 250403A: Montarrenti Observatory optical detection
  6. GRB 250403A: KAIT optical observations
  7. GRB 250403A: Fermi GBM observations
  8. GRB 250403A: Swift/UVOT Detection
  9. GRB 250403A: SVOM/VT optical observation
  10. GRB 250403A: REM NIR afterglow detection
  11. GRB 250403A: LCO optical counterpart detection
  12. GRB 250403A: JinShan optical observations
  13. GRB 250403A: Optical counterpart detection by LCO.
  14. GRB 250403A: Swift-XRT observations
  15. Fermi GRB 250403A: Global MASTER-Net observations report
  16. GRB 250403A: GOTO optical counterpart follow-up observations
  17. GRB 250403A: GMG Optical Observation
  18. GRB 250403A: 1.6m Mephisto multi-band optical detection
  19. GRB 250403A: SVOM/C-GFT optical observations
  20. GRB 250403A: GOTO detection of the optical afterglow
  21. GRB 250403A : SVOM detection of a burst
  22. GRB 250403A: Fermi GBM Final Real-time Localization

Advanced

Download all Circulars as a .tar.gz archive:
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